The present invention relates to esophageal stethoscopes, and, in particular, to a reusable measuring attachment having an adjustably-positionable sensing probe for use with a variety of sizes and types of esophageal stethoscopes.
The conventional esophageal stethoscope consists of a long, transparent, hollow plastic tube open at its proximal end and perforated adjacent its distal end with a group of cylindrically-spaced holes. The distal end of the tube and the group of spaced holes is closed and hermetically sealed by a thin, flexible, cylindrical cuff or sheath surrounding the distal end portion. The open proximal end of certain esophageal stethoscopes is provided with a securely attached plastic connector for acoustically coupling the stethoscope to the flexible rubber tubing of the physician's earpiece.
Esophageal stethoscope are available in different sizes and lengths from 12 French, for use in pediatrics, to 24 French, for large adult patients. Length generally exceeds 50 centimeters. The distal end of the stethoscope is intubated through the patient's mouth, past the oral pharynx and into the esophagus. The stethoscope may be positioned at varying depths to monitor the patient's body sounds at different locations in the esophageal region. The esophageal stethoscope must be discarded after use and cannot be reused.
The temperature of the patient may be measured by an esophageal stethoscope provided with a thermocouple or thermistor situated in the distal end portion and electrically connected to a pair of conductive wires. In one prior art embodiment, a thermocouple is securely attached to the inside wall of the distal end portion, and the conductive wires pass out under a rigid plastic connector sealed to the proximal end of the stethoscope. In another embodiment, a thermistor is situated inside the distal end adjacent the thin, flexible cuff, and the conductive wires are attached to a pair of end terminals mounted in the rigid plastic connector at the proximal end of the stethoscope.
The prior esophageal stethoscope have not been entirely satisfactory and possess a number of disadvantages and problems. When provided with a rigid plastic connector sealed or rigidly attached to the proximal end, it has been difficult to alter the length of the stethoscope. This places a restraint upon the physician and he must use stethoscope of fixed, predetermined length. When a temperature-sensing element forms an integral part of the stethoscope, altering the length of the stethoscope is substantially impossible.
When the type of temperature-sensing element differs from stethoscope to stethoscope, it is necessary for the hospital to maintain and have available the appropriate temperature-measuring instrument which, of necessity, must be calibrated with each different sensing element if accurate measurements are to be made. This problem is compounded since the esophageal stethoscope with its integral temperature-sensing element and electrical connections must be discarded after use and cannot be reused.
The present invention overcomes these serious problems by providing a universal measuring attachment for use with different sizes and types of esophageal stethoscopes and which may be sterilized and reused over an extended period of time. In addition, the measuring attachment is provided with an adjustably-positionable sensing probe which may be placed at any desired location within the stethoscope.
The sensing probe may be inserted into or withdrawn from the stethoscope, even during an operation, without disturbing the intubated stethoscope, thereby minimizing trauma to the patient. The invention not only reduces hospital costs by eliminating waste resulting from disposal but provides increased reliability and accuracy of measurements by employing reusable higher quality component parts, minimizing the need for recalibration.